Ask screenwriter Adam Herz what's the funniest thing about building a contemporary dream house high in the Hollywood Hills, and the comic maestro behind the 1999 blockbuster movie American Pie and its two sequels insists there wasn't a single laugh. "People say, 'Oh, you should write a movie about it,'" Herz says. After a pause, he adds, "Trust me. It wasn't funny."

It is a pity he won't consider developing a screenplay based on the three-year ordeal of squeezing 4,320 square feet of house onto a tiny polygonal lot in one of the most celebrated (and celebrity-laden) neighborhoods in Los Angeles. The characters involved seem ready-made for a remake of The Money Pit. There is Herz, the self-described dude from Grand Rapids, Michigan, a brain surgeon's son who admits to knowing dismayingly little about the trials of construction. There is the sweetly supportive wife, Laurie (she is giving birth to the couple's first child right about now). And last but not least there is the interior-decorator sidekick, a trifle eccentric and devastatingly quick with a bon mot. That particular role was embodied by Peter Dunham, a British expat known for a worldly bohemian taste that has become a leitmotif among Southern California's young creative set. "Adam is such a perfectionist Virgo," the decorator says. Still, he notes, "He and Laurie were great clients because they indulged my craziness for custom everything."

Dunham was brought in on the recommendation of Adam's business manager, one of Dunham's admiring clients, just as the Herzes' house was being framed out. Though the relatively steep property mandated a vertical home -- architect Richard Gemigniani incorporated plenty of glass to take in those vertiginous views of scrubby hillsides and precariously perched split-levels -- the screenwriter feared the end result would be too austere. "We didn't want it to be just another plaster box in the Hills," Adam says. "I wanted warmth and heart. I wanted it to be welcoming. Peter is very aware of how space is used." Which is a good characteristic to have when faced with a client who says that when the project began, he owned "functionally nothing" save for a living room and bedroom set. "I had no idea how to furnish a house," he says.

Luckily Dunham was up for the challenge of carving what he calls "nestle-in areas" out of the high, square living spaces and softening them with natural-fiber textiles and earthy elements like California art pottery, hand-carved-stone light fixtures, and comfortable seating. At the top of his agenda was taking the architecture's regional characteristics in hand and giving them an unexpected spin. "We wanted to get away from the upside-down house that's so common here," says Dunham, referring to residences whose hillside placement means that the front door opens to the bedroom floor and a staircase leads down to the entertainment areas. His solution was ingenious. "We made a reception room out of a bedroom on the entry floor," the decorator explains. "That way you walk in and see L.A. in the distance, all magnificent and sparkly."

Adjacent to the reception room is Laurie's favorite space, a library lined with cerused-oak paneling. "I don't like to leave this spot," she asserts, and frankly there is no reason for her to, thanks to the hideaway refrigerator drawers and wet bar. "I'm really into gadgetry, and I hate wasted space," Adam confides. Among his home improvements are three icemakers placed at handy points throughout the house. Says Dunham, "This place is like a boat with all the built-ins."

The decorator handily supplied the atmospheric warmth Adam requested and also worked in numerous thoughtful gestures. The walls of the master bedroom, for instance, are upholstered in denim-blue linen the exact shade of Laurie's eyes. Handwoven curtains with horizontal stripes -- "Peter has these magical weavers in Nepal," Adam says -- bring the living room's double-height windows down to a more intimate scale. A bamboo wall covering wraps the dining room, whose round table and marble-top sideboard are Dunham designs, as are many of the patterned fabrics in the house, some inspired by Central Asian textiles. And in the basement, which Adam describes as the heart of the house when it comes to entertaining, is a saloon with a polished mahogany bar and swinging doors, alongside a 14-seat home theater.

The environment Dunham has wrought on this particular slope of the Hollywood Hills is exactly what the screenwriter and his young family ordered -- cozy, comfortable, and colorful. Even Herz couldn't have scripted a more perfect ending.